1. Technical Field
The present invention relates in general to marine air conditioning systems and relates specifically a system, method, and apparatus for shielding sparks generated by a compressor in a marine air conditioning system.
2. Description of the Related Art
For many years, air conditioning units have been installed on boats to provide comfortable areas on the boat during warm weather. Various methods of cooling the air on boats have been used, including non-refrigerant cooling systems. However, a system using a compressed refrigerant is the most effective system in widespread use today.
In typical marine air conditioning systems, an electric motor drives a compressor for compressing refrigerant within a closed system. The refrigerant becomes heated as it is compressed, and it then passes through a condenser for cooling the refrigerant. The condenser may be an air-cooled unit, in which air passes over tubing in the condenser for drawing heat from the refrigerant as it passes through the condenser. Another type of condenser uses water to cool the refrigerant. A pump draws water through a hole in the hull of the boat and over the condenser tubes. Both methods sufficiently cool the refrigerant.
One disadvantage of using the current systems is that the electric motor typically requires the boat to be docked and connected to an outboard electrical source or to have an onboard generator. Without a generator, the system cannot be used when the boat is away from a dock. A disadvantage of a water-cooled system is that the system requires a separate water pump to pass water through the condenser. A related disadvantage is the additional holes in the hull that are required for the inlet and outlet of the pump for the condenser.
Many systems are available that use engine-driven compressors for compressing the refrigerant. However, these systems also use air-cooled condensers or water-cooled condensers that utilize a water pump in addition to that providing water to cool the engine. One solution to this problem is disclosed in the parent patent application in the present case, which is referenced above. That solution provides a marine air conditioning system having a water-cooled condenser that eliminates the need for a separate water pump for the condenser and the associated additional holes in the hull. Moreover, that system is operable while away from a dock.
Some air conditioner compressors utilize a clutch that cycles between engaged and disengaged positions by an electromagnetic coil. Movement of the clutch between these positions causes metal-to-metal contact and can be a source of sparks. For marine engines that operate on gasoline, this is a potentially hazardous situation in the bilge compartment since gas fumes can accumulate in the compartment if it is not properly vented.